From 6d367347bc175caedf66c8e68f66a23be8f298c2 Mon Sep 17 00:00:00 2001 From: Julien Grall Date: Fri, 30 Nov 2018 17:15:33 +0000 Subject: [PATCH] xen/arm: gic: Make sure the number of interrupt lines is valid before using it GICv2 and GICv3 supports up to 1020 interrupts. However, the value computed from GICD_TYPER.ITLinesNumber can be up to 1024. On GICv3, we will end up to write in reserved registers that are right after the IROUTERs one as the value is not capped early enough. Cap the number of interrupts as soon as we compute it so we know we can safely using it afterwards. Signed-off-by: Julien Grall Reported-by: Jan-Peter Larsson Reviewed-by: Stefano Stabellini Release-Acked-by: Juergen Gross (cherry picked from commit 30f5047b2c4e577436b505ba7627f34c3be02014) --- xen/arch/arm/gic-v2.c | 7 ++++--- xen/arch/arm/gic-v3.c | 7 ++++--- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c index d2dcafb6a3..d01b9c6aab 100644 --- a/xen/arch/arm/gic-v2.c +++ b/xen/arch/arm/gic-v2.c @@ -353,6 +353,10 @@ static void __init gicv2_dist_init(void) type = readl_gicd(GICD_TYPER); nr_lines = 32 * ((type & GICD_TYPE_LINES) + 1); + /* Only 1020 interrupts are supported */ + nr_lines = min(1020U, nr_lines); + gicv2_info.nr_lines = nr_lines; + gic_cpus = 1 + ((type & GICD_TYPE_CPUS) >> 5); printk("GICv2: %d lines, %d cpu%s%s (IID %8.8x).\n", nr_lines, gic_cpus, (gic_cpus == 1) ? "" : "s", @@ -377,9 +381,6 @@ static void __init gicv2_dist_init(void) for ( i = 32; i < nr_lines; i += 32 ) writel_gicd(~0x0, GICD_ICENABLER + (i / 32) * 4); - /* Only 1020 interrupts are supported */ - gicv2_info.nr_lines = min(1020U, nr_lines); - /* Turn on the distributor */ writel_gicd(GICD_CTL_ENABLE, GICD_CTLR); } diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c index a6ed0d8f22..f53a3fe65e 100644 --- a/xen/arch/arm/gic-v3.c +++ b/xen/arch/arm/gic-v3.c @@ -609,6 +609,10 @@ static void __init gicv3_dist_init(void) if ( type & GICD_TYPE_LPIS ) gicv3_lpi_init_host_lpis(GICD_TYPE_ID_BITS(type)); + /* Only 1020 interrupts are supported */ + nr_lines = min(1020U, nr_lines); + gicv3_info.nr_lines = nr_lines; + printk("GICv3: %d lines, (IID %8.8x).\n", nr_lines, readl_relaxed(GICD + GICD_IIDR)); @@ -648,9 +652,6 @@ static void __init gicv3_dist_init(void) for ( i = NR_GIC_LOCAL_IRQS; i < nr_lines; i++ ) writeq_relaxed(affinity, GICD + GICD_IROUTER + i * 8); - - /* Only 1020 interrupts are supported */ - gicv3_info.nr_lines = min(1020U, nr_lines); } static int gicv3_enable_redist(void) -- 2.30.2